Liquid crystal displays (LCDs) are commonly used as display devices for compact electronic apparatuses because of their capability of displaying images with good quality while using little power. However, the liquid crystals in an LCD do not emit any light themselves. The liquid crystals have to be lit up by a light source so as to clearly and sharply display text and images. Usually, a backlight device is employed as such a light source.
Typically, a backlight device comprises a plurality of light emitting diodes (LEDs), which are arranged in the form of a matrix. FIG. 7 shows a conventional LED backlight device 700, where a plurality of LEDs 710 are arranged along a row direction 770 and a column direction 772 such that any two adjacent rows have an identical pitch, Prow, therebetween and any two adjacent columns have an identical pitch, Pcol, therebetween. Such an arrangement of the backlight device needs more LEDs, thereby increasing the cost of the backlight device. Simply reducing the number of LEDs, however, is not a solution because it may affect the uniformity of the light.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.